output '}' as wxChar, not char, which results in using the int overload of operator<<() in Unicode build (patch 1682643) [backport from HEAD]

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@44868 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/config.cpp

@@ -424,7 +424,7 @@ wxString wxExpandEnvVars(const wxString& str)
             else {
               // skip closing bracket unless the variables wasn't expanded
               if ( pszValue == NULL )
-                strResult << (char)bracket;
+                strResult << (wxChar)bracket;
               m++;
             }
           }